High-frequency tube structure



Dec. 6, 1949 w. T. COOKE ET Al.

HIGH-FREQUENCY TUBE STRUCTURE Z'She'etS-Sheet 1 Filed June 28, 1940 mm N M+ ww m w, iQ :5 mm v MC .lll 1T.` 1il l 1 M l L l 'I l f,l .v @W s i MS. l m M l. 1-1 il] ||-m\-l M Szmrld. n. Q. .3 uw vv L L ammi vn om y n M mw m w` Il. I 'l m HUHHH. l ,I n l Q\ M 1 HUHUHHIIWH 1 l .n.mmmmunm.. w W l I Q 1| `h l L .w .3 N L mm vn .m w A G n 4 O Nv N1 \|U\ TOL-J.' CALDWELL, J'R., DA v1 G.- CLI O PD.,

ATTORNE Dec. 6, 1949 w, T, COOKE ET AL 2,490,030

HIGH-FREQUENCY TUBE STRUCTURE Filed June 28, 1940 2 Sheets-Sheet 2 l INVENToRs WILL/AM T COOKE. JEJ.' CALDWELLJR.

A /D L/FFO `D. BY

TTORN Y.

Patented Dec. 6, 1949 HIGH-FREQUENCY TUBE STRUCTURE William T. Cooke and Joe J. Caldwell, Jr., Palo Alto, Calif., and David G. Clifford, Montclair, N. J., assignors to The Sperry Corporation, a

corporation of Delaware Application June 28, 1940, Serial No. 342,912

structure for electron-beam tubes using cavity resonators, adapted for eflicient collection of electrons and dissipation of their kinetic energy after they have served their useful purpose in the tube.

A further object is to provide an improved grid structure, especially adapted for use with cavity resonators, and easily fabricated into tubes of the present type.

Other objects and advantages will become apparent from the specification, taken in connection with the accompanying drawings wherein the invention is embodied in concrete form.

In the drawings:

Fig. 1 is a longitudinal sectional view of a tube structure in which the present invention may be used, with the tuning means removed therefrom.

Fig. 2 is a partial sectional view in plan with parts broken away showing the tube structure of Fig. 1 assembled with its tuning means.

Fig. 3 is a view in elevation of the tube structure of Fig. 1 and tuning means therefor.

Fig. 4 is a view in elevation of the novel grid of the present invention.

Fig. 5 is a partial longitudinal sectional view of a modied tube structure incorporating the novel electron collector of the present invention, and

Fig. 6 is an enlarged sectional detailed view of a portion of the structure of Fig. 5.

Similar characters of reference are used in all of the above figures to indicate corresponding parts.

Referring now to the structure of Figs. 1 to 3 of the drawings, the reference numeral I designates a base upon which the high frequency tube structure is adapted to be supported. Base I has upstanding posts 2 and 2', post 2 being provided with a suitable groove in its upper portion for xedly receiving an annular flange 3 provided on the resonator casing 4 of the tube structure.

The casing 4 is shown of cylindrical shape and is provided with ends consisting of annular corrugated and iiexible diaphragms 5 and 5 which are joined at their outer peripheries to the rigid cylindrical portion of casing 4 and are connected 26 Claims. (CI. Z50-27.5)

at their inner peripheries to aligned tubular projections 6 and 6' provided on cylindrical end shells 8 and 8 of the tube structure. End shell 8' has an indirectly heated cathode structure 2l therewithin, the filament of the cathode being supplied through leads 22 and 23, extending through the press 2l provided in the sealing bell 28. A heat retaining and focussing sleeve 24 surrounds the emitter 2|. An additional focussing ring 25 is positioned in front of the cathode assembly 2 I-24 vfor the purpose of collimating'the electron stream leaving cathode 2l. 'lhis ring 25 is adapted to be connected to a suitable external potential by way of lead 26 extending through the press 21. A space charge control grid 29 is shown located in front of the emitter 2|, this grid being shown as a stocking weave and having its periphery conned between the two rings of an annular supporting member 30, which member is connected to an external lead 3I adapted to be connected, for example, to a suitable modulation source. A stream of electrons as collimated by ring 25 passes through tubular projections 6 and S and centrally through the resonator casing 4.

The rigid cylindrical shell of the casing 4 is provided on its inner surface with an internally projectingflange 1 that serves to space apart two spun resonator diaphragms 9 and 9', these diaphragms being formedwith oppositely projecting tubular neck portions Ill and I0 that are aligned with, though slightlyT separated from, the inner ends of the tubular projections 6 and 6'. The opposed ends of tubular member 6 and neck portion l0 are provided with opposed grids II. Similarly, the opposed ends of tubular member 6 and neck portion I0 are provided with opposed grids Il.

As thus constructed, two hollow or cavity resonators I2 and I2 are formed within the interior of resonator casing 4, the resonator l2 being deined by the space between flexible diaphragm 5 and diaphragm 9 and the other resonator I2 being defined by the space between exible diaphragm 5 and diaphragm 9. A feedback or coupling loop I3 is shown extending through diaphragms 9 and 9 for coupling the oscillating electromagnetic iields of resonators I2 and I2' as when the tube structure is employed as an oscillator or regenerative amplifier.

The ends of the tubular projections 6 and 6' joining the shells 8 and 8 are shown provided with grids I5 and I5' that are similar to grids I-I. The construction of these grids II and I5 is shown in detail in Fig. 4. These grids consist of an outer ring I6, to the inner surface of which are secured, as by spot welding, a series of approximately J-shaped grid elements. These grid elements each comprise radially inwardly projecting long and short legs II and I8 which are connected together at the ring I6 by a connecting portion I9. Thus, in producing this grid a series of the J-shapedv grid elements are made and then are secured in mutually spaced relation to the inner surface of ring I6. This grid has the advantage of simple construction, ease of assembly and is not injured by thermal expansion and contraction of legs I1 and I8 in use since the inner ends of these legs are free.

The end shell 8 has a detector grid kassembly contained therewithin, thisy alsslemlly`V Iconsisting of spaced grids 32 and 32 that are carried by a sleeve 33 having a lead 34 connected thereto and extending outwardly through the press 35 of the sealing bell 36 for connection to a suitable source of potential.

A collimating ring 3l is positioned in advance of the grids 32 and 32' and is connected by a lead 3 8 to a suitable source or potential, whereby this nring will serve to reduce any dispersive tendencies of the stream, While the same is approaching grids 32 and 32. A collecting plate 39 is provided and connected to external lead'4 for conveying away electrons passing through grids 32 and 32.

Resonator I2 is shown provided with a concentric line terminal post 4I that extends through the cylindrical wall of resonator casing 4 and has an internal loop 42 for supplying energy to or removing the same from the interior of resonator I2. If desired the resonator I2 may also be provided with a concentric line terminal post or posts as illustrated.

Assuming that the tube apparatus has been evacuated and is connected for operating as a receiver, for example, the electron stream from emitter 2| in passing between grids II of resonator I2 will have its velocity recurrently altered kdue to its passage through the relatively weak alternating eld ,set up in resonator I2 by the action of terminal post loop 42 supplied from a suitable antenna or other high frequency source. Irivth'e drift space I4 provided within casing 4 between resonator I2' and resonator I2, the faster electrons will overtake the normal velocity electrons, while the latter will overtake the slower electrons so that the electrons enter resonator I2 in groups and set up therein an amplified version ofthe standing field in resonator I2 as is explained in the above mentioned patent. Owing tothe fact that the diaphragms 9 and 9 ilare away from the electron stream to provide a relatively large annular space around the stream in the drift space, dispersive action of the drift space walls on the stream is reduced to a minimum, thereby aiding in preventing spreading oi .the beam. Also, by having the drift space co extensive with the resonators I2 and I2, the overall dimension of the tube is greatly reduced, thereby shortening the electron stream and aiding in preventing spreading of the same. For eicient operation it will be apparent that the collimated beam leaving emitter 2l should pass through the resonators and the drift space and thereafter approach detector grids 32 and 32' Without appreciable spreading.

When the tube structure is used as an oscillator, feed-back can be obtained either by using loop I3 or by coupling the terminal posts 4I of resonators I2 and I2 by a detachable concentric line. If modulation is desired, the modulation potential is applied to space charge control grid 29. The output of resonator I2 may be connected to an antenna by coupling the latter to a terminal post 4I of resonator I2.

Referring now to the tuning means shown in Figs. 2 and 3, the end portions o1" tubular guide sleeves 43 and 43 are threaded through apertures provided in post 2 o n opposite sides of the casing 4 andare xed to this post as by lock nuts 44. Sleeves 43 and 43' extend slidably through additional sleeves 45 and 45. Sleeves l5 and 45 have inner end portions threaded through apertures provided in a yoke 46 that is fixed upon a ilange` 41 secured to the end shell 8'. The outer end portions of sleeves 45 and 45 are secured to a cross-head 46 that is provided with a centrai tubular extension 49 into which is adjustably threaded a plug 59 provided on the inner end portion of a rod 5I, the outer end portion of which has a knurled knob 52 fixed thereon. Rod 5I is provided with a collar 53 abutting shoulder 54 provided on a tubular projection 55 provided on the post 2. The outer ends of tubular guide sleeves 43 and 43' are secured within apertures provided within post 2'.

A second knurled knob 56 is turnably mounted upon the rod 5I and has a hub portion 56 that is adjustably threaded into a tubular extension 57 provided on a cross-head 58 having the ends of rods 59 and 59 secured thereto, which rods are slidable longitudinally within the guide sleeves 43 and 43. The other ends of rods 59 and 59 are secured to a yoke 60 that is xed upon a flange 6I attached to the end shell 8. Knurled knob- 56 is provided with a tubular extension 62 that surrounds the rodl 5I and houses a rather stiff compression spring 63 which bears at one end against the knob 56 and at its other end against an antifriction bearing 64 carried by knob 52. This spring serves to take up any back lash that may be present in` the threads of the tuning means.

In use, since post s 2 and 2 are Xed upon the base I, the guide sleeves 4,3 and 43 together with resonator casing 4 and tubular projection 5 5 are held stationary. By turning knob 56 the tubular extension 51 of cross-head 58 is moved to the right or left with respect to extension 55 depending on which direction knob 56 is turned, thereby moving cross-head 58and rods 59 and 59 to effect a corresponding movement of yoke 66 and flange 6I and serving to elect relative movement of grids II of the resonator I2, the ilexible corrugated diaphragm 5 permitting such relative movement to take place. Thus, by turning knob 56, resonator I2 may be tuned to resonator I2. Similarly, by turning knob 52 the rod 5I is turned, thereby effecting longitudinal movement of tubular extension 49 provided on cross-head 48 and eiecting longitudinal movement of sleeves 45 and 45 which in turn eiect relative movement of the grids Il of resonator I2', thereby tuning this resonator with respect to resonator I2. If desired, both knobs 5,6 and 52 may be turned simultaneously thereby effecting gang tuning of the resonators. These knogs are provided With graduations 66 and 66 cooperating with a xed index 67 for indicating the amount of tuning. Owing to the great ilexibility of the diaphragms 5 and 5 the resonators may be tuned an indenite number of times without injury thereto.

The tube structure of Figs. 5 and 6 is even more compact than that shown in Fig. 1, the structures of these latter gures being especially suitable for use with somewhat longer wave lengths of the order o f 40 om., `for example. In this form of the invention the two resonator casings 61 and 68 are formed with outwardly directed aligned tubular extensions 69 and 10 carrying grids H at their inner ends. The emitter structure 1I is contained within tubular extension 69 and is shown provided with a plurality of mutually spaced heat baffles 12 and 13 for the purpose of preventing undue heating of the press 14.

Tuning in this form of the invention is accomplished by use of threaded collars 15 and 16 fixed upon the extensions 69 and 10, which collars 'have ltuning knobs 11 and 18 threaded thereon, which nuts act through anti-friction bearings 19 and 19 to press ring members 80 and 8| against the .outer peripheral portions of resonators 61 and 68.

Thus, by turning knobs 11 and 18, the portions of casings I61 and 68 extending between the ring members 80 and 8| and collars 15 and 16 are deilected resulting in relative movement of the grids of the resonators and hence tuning the same. The tubular extension 18 is provided with a frusto-conical or tapered portion 10' having cooling fins 82 to elect cooling of this portion of the tube structure, which serves to collect electrons passing through the resonators and through additional grids 83. Extension 10 and tapered portion 10' together constitute a collector means for `the electrons.

A novel form of concentric line terminal'post 84 is shown in Fig. 5. In this terminal DQSt. a glass seal 85 is secured at its outer periphery to the cylindrical casing of post 84 and at its inner periphery to an extremely thin portion of a metal tube 86 as of copper. Owing' to the thinness of this tube portion 86 under seal 85, the metal ilexes under thermal expansion and contraction so that the seal is not broken between the glass and the tube. The tube 86 is further reinforced by an inner tube 81 having its portion 88 underlying the seal 85 spaced inwardly from tube 86 to facilitate relative radial movement of tube 86. The loop 89 is attached at one end to the outer casing of the terminal post and at its other end this loop projects into inner tube 81 and is secured therein.

The structure disclosed but not claimed herein and including the terminal post, detector, tube and tuner arrangements is described and claimed lin our copending divisional application Serial No. 479,296, led March 15, 1943, now Patent Number 2,463,519 granted March 8, 1949.

As many changes could be made in the above construction and many apparently widely diierent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A grid structure comprising a ring member having a plurality of mutually spaced J-shaped grid elements secured thereto, each of said grid 4elements comprising a short and along leg and lbeing secured to said ring member at one end with said legs extending radially inwardly of said ring member but terminating short of the center of said ring member.

5 2. A grid structure comprising a ring member having a plurality of discrete integral grid elements secured thereto, each of said grid elements comprising mutually spaced long and short legs and a connecting portion, the latter portion being secured to said ring member with said legs extending substantially radially inwardly thereof but terminating short of the center of said ring member.

3. A grid structure comprising a plurality of separate integral grid elements, each of said grid elements comprising a short and a long leg joined at one end by an arcuate cross-piece, and joining means securing said cross-pieces in a circular arrangement with said legs extending radially inwardly thereof but terminating short of the center thereof.

4. A grid structure comprising a plurality of discrete integral grid elements, each of said grid elements comprising mutually spaced legs and a connecting portion, and joining means securing said connecting portions in a circular arrangement with said legs extending substantially radially inwardly thereof.

5. A grid structure comprising a ring member and a plurality of discrete integral grid elements, each of said elements comprising mutually spaced -legs and a connecting portion, all said latter portions being secured to said ring member with said legs extending substantially radially inwardly thereof..

6. A resonator structure comprising a hollowbody resonator having openings therethrough for the passage of electrons, and a hollow collector enclosing the entire path of said electrons beyond said resonator, said collector being tapered in shape and converging toward the end remote from said resonator.

7. A discharge device comprising a cathode, a hollow body resonator having entrance and exit openings therethrough for the passage of electrons, an extension of said resonator surrounding said exit openings, said extension having a tapered closed portion.

8, A discharge device comprising a cathode, a hollow body resonator having entrance and exit openings for electrons, and a tapered electron collector means having its base completely surrounding the exit openings in said hollow body resonator for preventing lateral escape of electrons which pass through said exit openings.

9. A discharge device comprising a hollow body resonator having two parallel spaced input and exit openings for the passage of electrons therethrough and a collector means about the exit opening of said resonator having a portion constituting an electron-intercepting surface of which the part nearest said openings forms an angle of incidence greater than 45 to the path of electrons emerging from said resonator that the electrons are scattered over the surface of said collector and on reflecting therefrom will continue in a generally forward direction.

10. Electron discharge device comprising first and second hollow resonators, means for projecting a stream of electrons through the interiors of said resonators in succession, said means including a cathode positioned on one side of said 'two resonators and outside the iield of said rst resonator, and a -collector positioned on the other side of said two resonators and outside the field of said second resonator and in a straight line with said cathode and enclosing the entire path of said stream beyond said resonators, said collector being tapered in shape with its narrow end remote from said resonators.

11. Electron discharge device comprising first and second hollow resonators, each of said resonators having two parallel spaced input and exit openings for the passage of electrons, the exit opening of said iirst resonator being spaced from the input opening of said second resonator by a 'idistaince at least as great as the distancev between the input and exit openings of lany onepfffsaid resonators, means for projecting a stream of electrons through the openings of said resonators in succession, said means including a cathode positioned on one side of said two resonators and outside theeld of said first resonator, and a collector positioned on the other sideof said two resonators and outside the field of said second resonator and in a straight line withzsaid cathode and enclosing the entire path of said stream beyond said resonators, said collector being tapered in shape with its narrow end remote from said resonators.

12. Electron discharge device comprising yfirst and second hollow resonators, means for project'- ing a stream of electrons through the interiors of said resonators in succession, said means including a cathode positioned on one side-of said vtwo resonators and outside the field of said rst resonator, and a collector positioned on the other side of said two resonators and outside the eld Iof said second resonator and in a straight line with said cathode, said collector lbeing tapered in shape with its narrow end remote from said resonator, and a load circuit in the form of a loop of conductor in the interior of said second resonator.

13. A resonator structure comprising a hollow .body resonator having openings therethrough for the passage of electrons, and a hollow collector enclosing `the entire path of said electrons beyond said resonator, said collector having a portion thereof internally tapered and converging away from said resonator.

14. Electron discharge device comprising rst and second hollow resonators, means for projecting a stream of electrons throughithe interiors of saidresonators in succession, saidmeans. including a cathode positioned on one side of said two resonators and outside the field of said first resonator, and a hollow collector positioned in a straight line with said cathode on the other side of said two resonators and vacuouslysealed to said resonator to form part of the vvacuum envelope of said apparatus, said collector being internally tapered and converging away from said resonator.

15. Electron discharge device comprising rst and second hollow resonators, each-of said resonators having two parallel spaced input and exit openings for the passage of electrons, the exit opening of said'rst resonator being spaced from the input yopening of said second resonator by a distance at least as great as the distance between the input and exit openings of any one of said resonators, means for projecting a stream. "of 'electrons through the openings of said resonators in succession, said means including a cathode positioned on one side of said two resonators and 'outside the ield of said rst resonator, and `a collector positioned in a straight line with said cathode on the other side of said two resonators and enclosing the entire path of said stream beyond said second resonator, said collector having a portion tapered and converging away from said resonator.

i6. Electron discharge device comprising first and second hollow resonators, meansV ior projecting a stream of electrons through the-interiors of. said resonators in succession, said means including a cathode positioned on one side of said two resonators and outside the eld of said rst resonator, and a collector positionedin a straight .line with Said. cathode onv the other side of. said V;.

ramasse two resonators andfvacuously sealed to said res"- onators to for'm Itlxerewith part of the vacuum envelope of said apparatus, said collector having a portion tapered' in shape and converging away from said resonator, and a load circuit in the form' of a loop of conductor in the interior of said second resonator.

17. A discharge device comprising a hollowbody resonator having openings for the passage of electronstherethrough and an electron collector enclosing the entire path of said electrons beyond said resonator means and having its sides constituting an electron-intercepting surface oi which the part nearest said openings forms an angle of incidence greater than 45 to the path will not tend to concentrate on a local spot of said collector and on reflecting therefrom will continue -in a generally'forward direction.

19. Adischarge device comprising a hollowbody resonator having two parallel spaced input andfexit openings for the passage of electrons therethrough and a hollow surface collector means connected to said resonator and enclosing `the entire path of said electrons beyond said exit opening, theA cross-section of said collector means being closed and having a portion at a Very acute angle to the path of said electrons as they pass out of the. exit' opening of said hollow-body resonator.

20. A discharge device comprising a hollowbody resonator having two parallel spaced input and exit Vopenings for the passage of electrons therethrough and having a hollow surface collector means` vacuouslyy sealed to said resonator abouty said exit opening and forming a portion of the vacuum envelope of said device, the crosssection of said collectormeans having a closed perimeter with a porti-onat a very acutefangle to the path of said electronsas they pass out of the exit opening of said hollow-tbody resonator.

21. A hollow body resonator comprising a metal wall lhaving an lopening therethrough, a metal member having one face parallel with said opening, said metal member having anelectron receiving cavity in said face Vand a flexible metal sheet interconnecting said member and said wall.

22. A hollow body resonator comprising a metal wall having an opening therethrough, a metal block having one face parallel with said opening, saidmetal block having an electron receiving cavity in said face, and a eXible metal sheet interconnecting said block and'said wall, a casing connected to said wall andfilexible metal sheet` and adjusting 'means connected to said block and `based on said casing for positioning the face of said block in relationrto said opening.

23. vA hollow body resonator comprising a metal wall having an opening-therethrough, a metal block having one face parallel with said opening, saidmetalblock having an electron` receiving Icavity in said face, and a flexible metal sheet interconnecting said block and said wall.

24. A hollow body resonator comprising a metal Wall having an opening therethrough, a metal member having one face parallel with said opening, said metal member having an electron receiving cavity in said face and a iiexible metal sheet interconnecting said member and said wall, a casing connected to said wall and exible metal sheet and adjusting means connected to said member and based on said casing for positioning the face of said member in relation to said opening.

25. A hollow body resonator comprising a metal wall having an opening therethrough, a metal member having one face parallel with said opening, said metal member having an electronreceiving cavity in said face, a flexible metal sheet interconnecting said member and said wall, and adjusting means connected to the said meinber for positioning the face of said member in relation to said opening.

26. A hollow body resonator comprising a metal wall having 4an opening therethrough, a metal block having one face parallel with said opening, said metal block having an electron receiving cavity in said face and a ilexible metal 10 sheet interconnecting said block and said wall, the outer portion of said block having fins attached thereto.

WILLIAM T. COOKE. JOE J. CALDWELL, JR. DAVID G. CLIFFORD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS OTHER REFERENCES Journal of Applied Physics, vol. 10, No. 5, May 1939, DD. 321-327, 

